Body timing

Although the existence of circadian clock–dependent modulation of gene expression in humans has been known for more than a decade, the relevance of the circadian clock in drug response and therapeutic outcome has been only recently appreciated. Now, Ruben et al. used an algorithm called cyclic ordering by periodic structure (CYCLOPS) to create a database of cycling genes in 13 human tissues. The authors show that several rhythmically expressed genes code for known drug targets or for proteins involved in drug transport and metabolism. The data represent a useful resource for circadian medicine and strengthen the notion that circadian rhythms should be considered when determining therapeutic interventions.